Mix the ingredients for the orange swirl in one bowl and the ingredients for the vanilla swirl in another. Put each mixture in a ziplock bag and cut a tiny hole in the corner. Pipe the yogurt into popsicle molds, (you want it to be uneven because the orange juice will fill in the gaps), and then follow with the orange juice. Give the popsicle mold a light tap on the counter so any air bubbles will rise to the top, and place sticks in each popsicle mold. Freeze overnight.
For a Quicker Version: Place all the ingredients (for both the vanilla and orange layer) into a blender, and blend everything together. Pour mixture into popsicle molds and freeze overnight. They will taste the same, but it will make for a much quicker prep!